ABS Global, Inc., Genus Plc, v. Cytonome/ST, LLC, [2022-1761] (October 19, 2023), the Federal Circuit reversed the Board’s finding of no unpatentability of claims 1 and 8 of U.S. Patent No. 10,583,439, and vacated the decision of no unpatentability of claims 2, 6, and 9. The ’439 patent, titled “Hydrodynamic Focusing Apparatus and Methods,” describes and claims a microfluidic device for “particle” processing.
The Board determined that, as a matter of claim construction, “the sample stream” language in claim 1 had a singular-only meaning, not allowing a plurality of streams or a split stream. The Board also rejected ABS’s obviousness challenges, and their reasoning depended on their claim construction that claim 1 required that there be only a single stream, precluding a split one.
The Federal Circuit rejected the PTAB’s construction, explaining that the specific claim language at issue is “a fluid focusing region configured to focus the sample stream.” The use of the definite article, “the,” means that the phrase “the sample stream” refers back to earlier language as an antecedent. The antecedent language is “a sample stream” in the preceding limitation, and it is the singular-only or plural- allowing meaning of that limitation which is determinative. The reference-back “the” language takes its meaning from the meaning of the antecedent, so if “a sample stream” has a plural-allowing meaning, so does the reference-back “the sample stream” phrase.
The Federal Circuit said two familiar aspects of claim-construction analysis strongly support the plural-allowing meaning here. First, “at least in an open-ended ‘comprising’ claim,” like claim 1 of the ’439 patent, “use of ‘a’ or ‘an’ before a noun naming an object” requires that the phrase be construed to mean “‘one or more’ unless the context sufficiently indicates otherwise.” Second, the specification here states: “[F]or the purposes of the present disclosure, the term ‘a’ or ‘an’ entity refers to one or more of that entity. As such, the terms ‘a’ or ‘an’, ‘one or more’ and ‘at least one’ can be used interchangeably herein.”
The Federal Circuit found no sufficient basis for rejecting the plural-allowing meaning of “a sample stream” here. The prosecution history has not been shown, or even meaningfully argued, to do so. Nor does anything in the specification supply a clear and manifest disavowal of that meaning, or totally negate it. In particular, the singular only meaning is not demanded by the specification’s embodiments, described as nothing more than examples.